MISSION OPERATIONS:
The NEAR-Shoemaker satellite continued to operate nominally this past week in orbit around the
asteroid 433 Eros. NEAR-Shoemaker has been in Operational Mode with Flight Computer #1 and
Attitude Interface Unit #2 in control. All instruments with the exception of the MSI (see below)
remained “ON” during this week. S/C attitude pointing continues to alternate between Eros nadir
proximity pointing, Earth pointing, and Sun pointing as required to conduct Eros orbital operations.
NEAR-Shoemaker completed its first month in Eros orbit on March 14.
NEAR-Shoemaker is presently in a 200 km by 209 km orbit around Eros. NEAR-Shoemaker will stay in
this orbit conducting Science observations until April 2, 2000 when an Orbit Correction Maneuver will
place the spacecraft in a 200 km x 100 km transfer orbit.
The March 15 Momentum Control Maneuver (MCM 1) successfully executed, biasing S/C momentum
with minimal perturbing effects on the orbit. This was a successful demonstration of the stand-alone
propulsive momentum adjustment design required to manage S/C angular momentum during weeks
when no Orbit Correction Maneuvers (OCM) are planned. A repeat of this maneuver is planned for
March 23.
The Multispectral Imager (MSI) experienced another command execution error on March 13 at 03:52
UTC suspending image taking until March 14 when Mission Operations rebooted the MSI at 19:30 UTC.
The investigation into this problem is ongoing.
Science activities conducted this week included Eros “high altitude” ~200 Km observations with the MSI,
NIS, MAG, NLR and XGRS instruments. Please consult science timelines for more details.
Mission Operations held a review of a modified Earth Safe Macro that prevents instruments from being
turned off during safing conditions when sufficient power is available. The modified Earth Safe Macro
will be uploaded to the spacecraft next week. Also reviewed was a new autonomy rule that will help
safeguard the spacecraft in the event automatic wheel speed de-saturations are required.
Upcoming Spacecraft Activities: In addition to regular Eros Science and Optical Navigation, the
following are operationally significant activities planned for the NEAR-Shoemaker future:
March 22 Propulsive Momentum Bias
April 2 Eros Orbit Correction Maneuver 3
(200 Km x 100 Km transfer orbit)